Thematische Bibliographien / Handheld laser scanning

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Auswahl der wissenschaftlichen Literatur zum Thema „Handheld laser scanning“

Autor: Grafiati

Veröffentlicht am 30. Juni 2021

Zuletzt aktualisiert am 15. Februar 2022

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Zeitschriftenartikel zum Thema "Handheld laser scanning"

DuBose, Theodore, Derek Nankivil, Francesco LaRocca, Gar Waterman, Kristen Hagan, James Polans, Brenton Keller et al. „Handheld adaptive optics scanning laser ophthalmoscope“. Optica 5, Nr. 9 (23.08.2018): 1027. http://dx.doi.org/10.1364/optica.5.001027.

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Hagan, Kristen, Theodore DuBose, David Cunefare, Gar Waterman, Jongwan Park, Corey Simmerer, Anthony N. Kuo, Ryan P. McNabb, Joseph A. Izatt und Sina Farsiu. „Multimodal handheld adaptive optics scanning laser ophthalmoscope“. Optics Letters 45, Nr. 17 (01.09.2020): 4940. http://dx.doi.org/10.1364/ol.402392.

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Komissarov, A. V., A. V. Remizov, M. M. Shlyakhova und K. K. Yambaev. „Handheld Laser Scanner Research“. Geodesy and Cartography 952, Nr. 10 (20.11.2019): 47–54. http://dx.doi.org/10.22389/0016-7126-2019-952-10-47-54.

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The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

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Bleier, M., und A. Nüchter. „TOWARDS ROBUST SELF-CALIBRATION FOR HANDHELD 3D LINE LASER SCANNING“. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W8 (13.11.2017): 31–36. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w8-31-2017.

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This paper studies self-calibration of a structured light system, which reconstructs 3D information using video from a static consumer camera and a handheld cross line laser projector. Intersections between the individual laser curves and geometric constraints on the relative position of the laser planes are exploited to achieve dense 3D reconstruction. This is possible without any prior knowledge of the movement of the projector. However, inaccurrately extracted laser lines introduce noise in the detected intersection positions and therefore distort the reconstruction result. Furthermore, when scanning objects with specular reflections, such as glossy painted or metalic surfaces, the reflections are often extracted from the camera image as erroneous laser curves. In this paper we investiagte how robust estimates of the parameters of the laser planes can be obtained despite of noisy detections.

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Sadeghi, F., H. Arefi, A. Fallah und M. Hahn. „3D BUILDING FAÇADE RECONSTRUCTION USING HANDHELD LASER SCANNING DATA“. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-1-W5 (11.12.2015): 625–30. http://dx.doi.org/10.5194/isprsarchives-xl-1-w5-625-2015.

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3D The three dimensional building modelling has been an interesting topic of research for decades and it seems that photogrammetry methods provide the only economic means to acquire truly 3D city data. According to the enormous developments of 3D building reconstruction with several applications such as navigation system, location based services and urban planning, the need to consider the semantic features (such as windows and doors) becomes more essential than ever, and therefore, a 3D model of buildings as block is not any more sufficient. To reconstruct the façade elements completely, we employed the high density point cloud data that obtained from the handheld laser scanner. The advantage of the handheld laser scanner with capability of direct acquisition of very dense 3D point clouds is that there is no need to derive three dimensional data from multi images using structure from motion techniques. This paper presents a grammar-based algorithm for façade reconstruction using handheld laser scanner data. The proposed method is a combination of bottom-up (data driven) and top-down (model driven) methods in which, at first the façade basic elements are extracted in a bottom-up way and then they are served as pre-knowledge for further processing to complete models especially in occluded and incomplete areas. The first step of data driven modelling is using the conditional RANSAC (RANdom SAmple Consensus) algorithm to detect façade plane in point cloud data and remove noisy objects like trees, pedestrians, traffic signs and poles. Then, the façade planes are divided into three depth layers to detect protrusion, indentation and wall points using density histogram. Due to an inappropriate reflection of laser beams from glasses, the windows appear like holes in point cloud data and therefore, can be distinguished and extracted easily from point cloud comparing to the other façade elements. Next step, is rasterizing the indentation layer that holds the windows and doors information. After rasterization process, the morphological operators are applied in order to remove small irrelevant objects. Next, the horizontal splitting lines are employed to determine floors and vertical splitting lines are employed to detect walls, windows, and doors. The windows, doors and walls elements which are named as terminals are clustered during classification process. Each terminal contains a special property as width. Among terminals, windows and doors are named the geometry tiles in definition of the vocabularies of grammar rules. Higher order structures that inferred by grouping the tiles resulted in the production rules. The rules with three dimensional modelled façade elements constitute formal grammar that is named façade grammar. This grammar holds all the information that is necessary to reconstruct façades in the style of the given building. Thus, it can be used to improve and complete façade reconstruction in areas with no or limited sensor data. Finally, a 3D reconstructed façade model is generated that the accuracy of its geometry size and geometry position depends on the density of the raw point cloud.

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LaRocca, Francesco, Derek Nankivil, Sina Farsiu und Joseph A. Izatt. „Handheld simultaneous scanning laser ophthalmoscopy and optical coherence tomography system“. Biomedical Optics Express 4, Nr. 11 (01.10.2013): 2307. http://dx.doi.org/10.1364/boe.4.002307.

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Yıldırım, I. D., B. Sarioglu und Y. D. Gokdel. „3D Printed Head for a Handheld Laser Scanning Confocal Microscope“. Instruments and Experimental Techniques 64, Nr. 2 (März 2021): 301–7. http://dx.doi.org/10.1134/s0020441221010176.

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Patil, Chetan A., Christopher L. Arrasmith, Mark A. Mackanos, David L. Dickensheets und Anita Mahadevan-Jansen. „A handheld laser scanning confocal reflectance imaging–confocal Raman microspectroscopy system“. Biomedical Optics Express 3, Nr. 3 (09.02.2012): 488. http://dx.doi.org/10.1364/boe.3.000488.

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LaRocca, Francesco, Derek Nankivil, Sina Farsiu und Joseph A. Izatt. „True color scanning laser ophthalmoscopy and optical coherence tomography handheld probe“. Biomedical Optics Express 5, Nr. 9 (27.08.2014): 3204. http://dx.doi.org/10.1364/boe.5.003204.

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Wang, Xiaomin, Zexiao Xie, Kun Wang und Liqin Zhou. „Research on a Handheld 3D Laser Scanning System for Measuring Large-Sized Objects“. Sensors 18, Nr. 10 (21.10.2018): 3567. http://dx.doi.org/10.3390/s18103567.

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A handheld 3D laser scanning system is proposed for measuring large-sized objects on site. This system is mainly composed of two CCD cameras and a line laser projector, in which the two CCD cameras constitute a binocular stereo vision system to locate the scanner’s position in the fixed workpiece coordinate system online, meanwhile the left CCD camera and the laser line projector constitute a structured light system to get the laser lines modulated by the workpiece features. The marked points and laser line are both obtained in the coordinate system of the left camera in each moment. To get the workpiece outline, the handheld scanner’s position is evaluated online by matching up the marked points got by the binocular stereo vision system and those in the workpiece coordinate system measured by a TRITOP system beforehand; then the laser line with workpiece’s features got at this moment is transformed into the fixed workpiece coordinate system. Finally, the 3D information composed by the laser lines can be reconstructed in the workpiece coordinate system. A ball arm with two standard balls, which is placed on a glass plate with many marked points randomly stuck on, is measured to test the system accuracy. The distance errors between the two balls are within ±0.05 mm, the radius errors of the two balls are all within ±0.04 mm, the distance errors from the scatter points to the fitted sphere are distributed evenly, within ±0.25 mm, without accumulated errors. Measurement results of two typical workpieces show that the system can measure large-sized objects completely with acceptable accuracy and have the advantage of avoiding some deficiencies, such as sheltering and limited measuring range.

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Dissertationen zum Thema "Handheld laser scanning"

Gustafsson, Amanda, und Olov Wängborg. „Mätosäkerhet vid digital terrängmodellering med handhållen laserskanner : Undersökning av den handhållna laserskannern ZEB-REVO“. Thesis, Högskolan i Gävle, Samhällsbyggnad, GIS, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-26841.

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En digital terrängmodell (DTM) är en representation av enbart själva markytan. Det finns flera metoder för att framställa DTM:er, där laserskanning har blivit en alltmer vanlig metod. Inom laserskanning är flygburen laserskanning (FLS) en flitigt använd metod, då metoden har fördelen av att kunna täcka stora områden på kort tid. Det finns dock nackdelar med FLS då datainsamlingen kan bli bristfällig i t.ex. skogsområden, där laserstrålar inte kan tränga igenom tät vegetation. Här kan handhållen laserskanning (HLS) vara ett bra alternativ då HLS går snabbt och inte behöver samma omfattande planering. Tidigare studier visar att HLS har många fördelar, men som dock inte kan hålla samma låga osäkerhet som terrester laserskanning (TLS). Det saknas däremot studier om hur HLS ställer sig mot mätningar med FLS. Syftet med studien är därför att utvärdera möjligheten att använda och tillämpa mätningar med HLS för framställning av DTM i skogsterräng gentemot FLS. Detta görs genom att jämföra respektive DTM:s lägesosäkerhet. I studien användes instrumentet ZEB-REVO för insamlingen av data för metoden HLS. Medan för FLS användes laserdata från Lantmäteriet. Från insamlad laserdata skapades därefter DTM:er. Dessa jämfördes mot ett antal kontrollprofiler som mättes in med totalstation. För respektive metod, HLS och FLS, beräknades medelvärde för höjdavvikelserna mot kontrollprofilerna där även standardavvikelse beräknades. Resultatet visar att DTM:en skapad av data från FLS beräknades ha en höjdavvikelse för hela området på 0,055 m som medelvärde gentemot inmätta kontrollprofiler. Standardavvikelsen för denna höjdavvikelse beräknades till 0,046 m för FLS. För DTM:en med data från HLS beräknades en höjdavvikelse på 0,043 m i medelvärde som bäst, där standardavvikelse beräknades till 0,034 m. Studien visar att metoderna HLS och FLS gav likvärdiga resultat gentemot de inmätta kontrollprofilerna, dock gav HLS generellt mindre standardavvikelse i jämförelse mot FLS. Vidare ansågs ZEB-REVO och dess tillhörande databearbetningsprogram GeoSLAM vara väldigt användarvänligt, där själva skanningen med instrumentet tog endast 10 minuter för studiens område på ca 2000 m2. Utifrån studiens resultat drogs slutsatsen att mätningar med HLS kan ge en likvärdig DTM, sett till osäkerheten, som FLS-mätningar. HLS kan därmed vara en kompletterande metod men att FLS är en fortsatt effektiv metod.
A digital terrain model (DTM) represent exclusively the earth surface. There are several methods which can be utilized to create DTMs, where laser scanning have become a common used method. Airborne laser scanning (ALS) is often used since the method can cover a large area in a relatively short time. However a disadvantage with ALS is that the data collection, for a wooded area, can be inadequate due to penetration difficulties for some laser beams. For that reason a handheld laser scanner (HLS) can be an alternative since measurements can be done fast and does not need the same extensive planning. Earlier studies mention HLS to have several advantages but can still not yet be compared with terrestrial laser scanning (TLS) concerning the measurements uncertainty. There are, however, no studies that investigates how measurements with HLS stands against FLS. The purpose with the study is to evaluate the ability to use measurements from HLS to create a DTM for a wooded area in comparison with ALS. This is done by comparing the different uncertainties for each DTM. In the study the acquisition of HLS laser data was collected with the instrument ZEB-REVO and the ALS laser data was received from Lantmäteriet (cadastral mapping and surveying authority in Sweden). After the data acquisition a DTM were created from each data set (method). The DTMs were then compared to control profiles, which have been measured with total station. From the comparison with the control profiles average height deviation and standard deviation were calculated for each DTM. The result shows that the DTM created from ALS data received an average height deviation of 0,055 m for the whole area with a standard deviation of 0,046 m. Corresponding result for the DTM created from HLS data were calculated, at best, to 0,043 m in average height deviation and 0,034 m in standard deviation. The study shows that the methods HLS and ALS gave equivalent result regarding the comparison with the control profiles, however HLS gave a generally lower value for standard deviation. Furthermore ZEB-REVO with its processing program GeoSLAM was considered to be very easy and user friendly. The area (approx. 2000 m2) for the study was scanned within only 10 min. The conclusion which were drawn from the obtained result was that measurements with HLS can generate an equivalent DTM, concerning the uncertainty, as measurements with FLS. Thereby HLS can be a complementing method but still FLS is seen as an effective method.

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Andersson, Elias. „Dokumentation av en trafikolycka med handhållen laserskanning och UAS-fotogrammetri : En utvärdering av punktmolnens lägesosäkerhet och visuella kvalitet“. Thesis, Högskolan i Gävle, Samhällsbyggnad, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36472.

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I samband med en trafikolycka är det ofta viktigt att återställa platsen till det normala så snabbt som möjligt. Emellanåt måste olycksplatsen dokumenteras för att orsaken till olyckan ska kunna utredas i ett senare skede. Traditionellt har detta arbete utförts genom att fotografera platsen och mäta olika avstånd. På senare tid har även terrester laserskanning kommit att bli ett tillförlitligt alternativ. Med det sagt är det tänkbart att även fotogrammetri och andra typer av laserskanning skulle kunna användas för att uppnå liknande resultat. Syftet med denna studie är att utforska hur handhållen laserskanning och UAS-fotogrammetri kan användas för att dokumentera en trafikolycka. Detta uppnås genom att utvärdera punktmolnens lägesosäkerhet och visuella kvalitet. Vidare utforskas fördelar och nackdelar med respektive metod, bland annat sett till tidsåtgång och kostnader, för att slutligen komma fram till vilken metod som lämpar sig bäst för att dokumentera en trafikolycka. En trafikolycka med två inblandade bilar iscensattes och laserskannades till en början med den handhållna laserskannern Leica BLK2GO. Därefter samlades bilder in med den obemannade flygfarkosten Leica Aibot följt av att ett referenspunktmoln skapades med den terrestra laserskannern Leica C10. Genom att jämföra koordinater för kontrollpunkter i referenspunktmolnet med koordinaterna för motsvarande kontrollpunkter i de två andra punktmolnen kunde deras lägesosäkerheter bestämmas. Studiens resultat visar att både punktmolnet som framställdes med handhållen laserskanning och UAS-fotogrammetri har en lägesosäkerhet (standardosäkerhet) i 3D på 0,019 m. Båda metoderna är tillämpliga för att dokumentera en trafikolycka, men jämfört med terrester laserskanning är punktmolnen dock bristfälliga på olika sätt. BLK2GO producerar ett förhållandevis mörkt punktmoln och mörka objekt avbildas sämre än ljusare föremål. I punktmolnet som framställdes med Leica Aibot förekom påtagliga håligheter i bilarnas karosser. Handhållen laserskanning är en tidseffektiv metod medan UAS-fotogrammetri kan utföras till en lägre kostnad. Sammanfattningsvis går det inte att dra någon entydig slutsats om vilken metod som lämpar sig bäst för att dokumentera en trafikolycka. Valet beror på vilka omständigheter som råder på olycksplatsen.
In the event of a traffic accident, it is often important to restore the site to its normal condition as fast as possible. Occasionally, the accident scene must be documented so that the cause of the accident can be investigated at a later stage. Traditionally, this work has been performed by taking pictures of the site and measuring different distances. Lately, terrestrial laser scanning has also become a reliable alternative. With that said, it is possible that photogrammetry and other types of laser scanning also could be utilized to achieve similar results. The aim of this study is to investigate how handheld laser scanning and UAS photogrammetry can be used to document a traffic accident. This is achieved by examining the positional uncertainty and visual quality of the point clouds. Moreover, the advantages and disadvantages of each method are explored, for instance in terms of time consumption and costs, in order to finally come to a conclusion of which method is best suited for documenting a traffic accident. A traffic accident with two involved cars was staged and initially laser scanned with the handheld laser scanner Leica BLK2GO. Thereafter, pictures were collected with the unmanned aerial vehicle Leica Aibot followed by the creation of a reference point cloud with the terrestrial laser scanner Leica C10. By comparing the coordinates of control points in the reference point cloud with the coordinates of the corresponding control points in the two other point clouds, their positional uncertainty could be determined. The results of the study show that both the point cloud produced by the handheld laser scanner and UAS photogrammetry have a positional uncertainty (standard uncertainty) of 0.019 m. Both methods are applicable for documenting a traffic accident but compared to terrestrial laser scanning, the point clouds are deficient in different ways. BLK2GO produces a relatively dark point cloud and dark objects are reproduced worse than lighter objects. In the point cloud produced by Leica Aibot, there were noticeable cavities in the bodies of the cars. Handheld laser scanning is a time-efficient method while UAS photogrammetry can be performed at a lower cost. In conclusion, it is not possible to arrive at an unambiguous conclusion with regards to which method that is best suited for documenting a traffic accident. The choice depends on the prevailing circumstances at the accident scene.

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Kumar, Karthik. „Microelectromechanical handheld laser-scanning confocal microscope: application to breast cancer imaging“. 2009. http://hdl.handle.net/2152/6974.

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Demographic data indicate that 60% of 6.7 million annual global cancer mortalities and 54% of 10.8 million new patients are in developing nations, unable or unwilling to avail of invasive screening tests that are the current norm. For most cancers, survival rate is strongly dependent on early detection, highlighting the need for improved screening methods. Studies have shown that cancers can be identified based on distinct sub-cellular morphological features and expression levels of specific molecular markers. Since 85% of cancers are known to originate in the epithelium, portable in vivo imaging techniques providing sub-cellular detail in tissue up to depths of 250 μm could help improve access to biopsy-free examination in low-infrastructure environments. The resultant early detection could dramatically improve patient prognosis, while reducing screening costs, treatment delay, and occurrences of unnecessary and potentially harmful medication. This dissertation investigates handheld instrumentation for laser-scanning confocal microscopy (LSCM) and its applicability to breast cancer detection and subsequent image-guided management. LSCM allows high-resolution mapping of spatial variations in refractive index or tumor marker expression within a single cell layer situated few hundred micrometers beneath the tissue surface. The main challenge facing miniaturization lies in the mechanism of beam deflection across the sample. The first part of the dissertation presents a fast, large-angle, high-reflectivity two-axis vertical comb driven silicon micromirror fabricated by a novel method compatible with complementary metal-oxide-semiconductor processing employed in the semiconductor industry. The process enables integration of rotation sensors on the chip to adaptively correct for aberrations in beam scanning while significantly reducing fabrication costs and barriers to market acceptance. The second part of the dissertation explores the integration of this micromirror with other optical and electronic components into a handheld laser-scanning confocal microscope. Applicability of the probe to epithelial breast cancer screening via reflectance and fluorescence imaging is investigated. Finally, enhanced imaging modalities based on the micromirror are presented. 3D cellular-level in vivo imaging via rapid swept-source optical coherence tomography is demonstrated. A method for “objective-less” microendoscopy, potentially resulting in substantially reduced probe dimensions, employing reflective binary-phase Fresnel zone plates monolithically integrated on the surface of the micromirror is presented.
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Bhatla, Ankit. „Generating as-built 3D models from photos taken by handheld digital camera“. Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-12-4618.

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As-built documentation is an essential set of records, consisting of construction drawings, specifications and equipment location, which are kept for facility management purposes. These documents are constantly being created and modified throughout the life of a project. This process is usually manual and fraught with errors, which inhibits reliable decision making. Technological advancements have made it possible to generate 3D models to assess as-built conditions for construction monitoring purposes, such as verifying conformance to baseline project schedules and contract specifications. For this purpose, 3D point clouds are widely generated using laser scanners. However, this approach has limitations in the construction industry due to the expensive and fragile equipment, lack of portability and need of trained operators. This study aims at investigating an alternate technology to generate as-built 3D point clouds using photos taken using handheld digital cameras, compare them against the original as-built 3D models, and check for accuracy of the modeling process. This analysis can aid in more reliable and effective decision making due to its cost effectiveness and ease of use, particularly in heavy infrastructure projects which are continually undergoing rehabilitation work. To achieve these objectives, a set of guidelines are developed for taking photographs that enable effective generation of 3D point clouds using off-the-shelf software packages. The accuracy of the modeling process is investigated using the results of the as-built 3D point cloud modeling of a 2000 feet under construction bridge in southern United States. Finally, the range of tolerance and deviation of element dimensions is determined by comparing the photo based model to the actual as-built model (developed using 2D drawings). Furthermore, to compare point clouds of laser scanning and photogrammetry, a laser scan and an image based survey of an exterior wall of a university building was also done. Results show that this technology in its present state is not suitable for modeling infrastructure projects, however technological developments can enable this to be an efficient way to extract measurements of inaccessible objects for progress monitoring purposes and the models can also be stored for future dimension takeoffs for decision making and asset management purposes.
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Nankivil, Derek. „Development of Swept Source Optical Coherence Tomography and Adaptive Optics Scanning Laser Ophthalmoscopy: Improved Imaging Speed and Handheld Applications“. Diss., 2016. http://hdl.handle.net/10161/12197.

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Optical coherence tomography (OCT) is a noninvasive three-dimensional interferometric imaging technique capable of achieving micrometer scale resolution. It is now a standard of care in ophthalmology, where it is used to improve the accuracy of early diagnosis, to better understand the source of pathophysiology, and to monitor disease progression and response to therapy. In particular, retinal imaging has been the most prevalent clinical application of OCT, but researchers and companies alike are developing OCT systems for cardiology, dermatology, dentistry, and many other medical and industrial applications.

Adaptive optics (AO) is a technique used to reduce monochromatic aberrations in optical instruments. It is used in astronomical telescopes, laser communications, high-power lasers, retinal imaging, optical fabrication and microscopy to improve system performance. Scanning laser ophthalmoscopy (SLO) is a noninvasive confocal imaging technique that produces high contrast two-dimensional retinal images. AO is combined with SLO (AOSLO) to compensate for the wavefront distortions caused by the optics of the eye, providing the ability to visualize the living retina with cellular resolution. AOSLO has shown great promise to advance the understanding of the etiology of retinal diseases on a cellular level.

Broadly, we endeavor to enhance the vision outcome of ophthalmic patients through improved diagnostics and personalized therapy. Toward this end, the objective of the work presented herein was the development of advanced techniques for increasing the imaging speed, reducing the form factor, and broadening the versatility of OCT and AOSLO. Despite our focus on applications in ophthalmology, the techniques developed could be applied to other medical and industrial applications. In this dissertation, a technique to quadruple the imaging speed of OCT was developed. This technique was demonstrated by imaging the retinas of healthy human subjects. A handheld, dual depth OCT system was developed. This system enabled sequential imaging of the anterior segment and retina of human eyes. Finally, handheld SLO/OCT systems were developed, culminating in the design of a handheld AOSLO system. This system has the potential to provide cellular level imaging of the human retina, resolving even the most densely packed foveal cones.

Dissertation

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LaRocca, Francesco. „Development of Multi-modal and Super-resolved Retinal Imaging Systems“. Diss., 2016. http://hdl.handle.net/10161/12239.

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Advancements in retinal imaging technologies have drastically improved the quality of eye care in the past couple decades. Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) are two examples of critical imaging modalities for the diagnosis of retinal pathologies. However current-generation SLO and OCT systems have limitations in diagnostic capability due to the following factors: the use of bulky tabletop systems, monochromatic imaging, and resolution degradation due to ocular aberrations and diffraction.

Bulky tabletop SLO and OCT systems are incapable of imaging patients that are supine, under anesthesia, or otherwise unable to maintain the required posture and fixation. Monochromatic SLO and OCT imaging prevents the identification of various color-specific diagnostic markers visible with color fundus photography like those of neovascular age-related macular degeneration. Resolution degradation due to ocular aberrations and diffraction has prevented the imaging of photoreceptors close to the fovea without the use of adaptive optics (AO), which require bulky and expensive components that limit the potential for widespread clinical use.

In this dissertation, techniques for extending the diagnostic capability of SLO and OCT systems are developed. These techniques include design strategies for miniaturizing and combining SLO and OCT to permit multi-modal, lightweight handheld probes to extend high quality retinal imaging to pediatric eye care. In addition, a method for extending true color retinal imaging to SLO to enable high-contrast, depth-resolved, high-fidelity color fundus imaging is demonstrated using a supercontinuum light source. Finally, the development and combination of SLO with a super-resolution confocal microscopy technique known as optical photon reassignment (OPRA) is demonstrated to enable high-resolution imaging of retinal photoreceptors without the use of adaptive optics.

Dissertation

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Buchteile zum Thema "Handheld laser scanning"

Puniach, E., und K. Widuch. „Comparative analysis of 3D archaeological documentation utilizing terrestrial laser scanning along with handheld scanning and photogrammetry“. In Topical Issues of Rational Use of Natural Resources 2019, 253–58. CRC Press, 2019. http://dx.doi.org/10.1201/9781003014577-32.

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Konferenzberichte zum Thema "Handheld laser scanning"

Nankivil, Derek, Francesco LaRocca, Sina Farsiu, Joseph A. Izatt, James M. Polans, Brenton Keller, Anthony N. Kuo, Lejla Vajzovic, Cynthia A. Toth und Theodore B. DuBose. „Handheld adaptive optics scanning laser ophthalmoscope for in vivo imaging of adults and infants (Conference Presentation)“. In Ophthalmic Technologies XXVIII, herausgegeben von Fabrice Manns, Per G. Söderberg und Arthur Ho. SPIE, 2018. http://dx.doi.org/10.1117/12.2289124.

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Hagan, Kristen, Theodore DuBose, David Cunefare, Corey Simmerer, Gar Waterman, Jongwan Park, Anthony N. Kuo, Ryan P. McNabb, Joseph A. Izatt und Sina Farsiu. „Wavefront sensorless multimodal handheld adaptive optics scanning laser ophthalmoscope for in vivo imaging of human retinal cones“. In Ophthalmic Technologies XXX, herausgegeben von Fabrice Manns, Per G. Söderberg und Arthur Ho. SPIE, 2020. http://dx.doi.org/10.1117/12.2544407.

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Makkonen, Tomi, Rauno Heikkilä, Pekka Tölli und Filip Fedorik. „Using SLAM-based Handheld Laser Scanning to Gain Information on Difficult-to-Access Areas for Use in Maintenance Model“. In 34th International Symposium on Automation and Robotics in Construction. Tribun EU, s.r.o., Brno, 2017. http://dx.doi.org/10.22260/isarc2017/0124.

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Teppati Losè, Lorenzo, Filiberto Chiabrando, Francesco Novelli, Giacomo Patrucco und Stefano Perri. „DOCUMENTATION OF A COMPLEX CULTURAL HERITAGE ASSET WITH INTEGRATED GEOMATIC SURVEY: THE MONTANARO BELL TOWER“. In ARQUEOLÓGICA 2.0 - 9th International Congress & 3rd GEORES - GEOmatics and pREServation. Editorial Universitat Politécnica de Valéncia: Editorial Universitat Politécnica de Valéncia, 2021. http://dx.doi.org/10.4995/arqueologica9.2021.12107.

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Annotation:

The research activities presented in this manuscript are focused on the documentation of a valuable built heritage asset: the Santa Marta bell tower (1769-1772), designed by the Italian architect Bernardo Antonio Vittone and located in the municipality of Montanaro (30 km North-East of Turin, Italy). The documentation of this complex palimpsest was designed to meet the requirements of the decay analysis and to provide a reference for the future restoration and valorisation project. To achieve these objectives a multi-scale and multi-sensor survey was designed and carried out exploiting several geomatics techniques (both range and image based). The fieldwork activities were firstly dedicated to the creation and measurement of a reference topographic network to be used as common local reference system for all the acquisitions as well as a series of control points (both inside and outside the bell towe) to be used for data orientation and accuracy assessment. Secondly, the exterior of the bell tower and its surroundings were imaged by means of an Unmanned Aerial Vehicle (UAV) and a set of Terrestrial Laser Scanning (TLS) acquisitions. The interior of the bell tower was sensed with two different rapid mapping approaches: using a handheld laser scanner based on the Simultaneous Localisation And Mapping (SLAM) technology and two different 360° cameras. All the acquired data were processed following both consolidated and experimental approaches and then integrated to generate traditional 2D architectural drawings supported by added value metric products. Of particular interest are the tests connected with the processing of the SLAM data and 360° images using a spherical photogrammetric approach that delivered preliminar encouraging results.

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Duma, V. F., D. Demian, C. Sinescu, R. Cernat, G. Dobre, M. L. Negrutiu, F. I. Topala, Gh Hutiu, A. Bradu und A. G. Podoleanu. „Handheld scanning probes for optical coherence tomography: developments, applications, and perspectives“. In Sixth International Conference on Lasers in Medicine, herausgegeben von Darinca Carmen Todea, Adrian G. Podoleanu und Virgil-Florin Duma. SPIE, 2016. http://dx.doi.org/10.1117/12.2178590.

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Duma, Virgil-Florin. „Scanning in biomedical imaging: from classical devices to handheld heads and micro-systems“. In Fifth International Conference on Lasers in Medicine, herausgegeben von Carmen Todea, Adrian G. Podoleanu und Virgil-Florin Duma. SPIE, 2014. http://dx.doi.org/10.1117/12.2042733.

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